1. Field of the Invention
The present invention relates to an electrical connector for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB).
2. Description of Prior Art
A conventional electrical connector for electrically connecting a CPU (not shown) with a PCB (not shown) generally comprises a housing, a plurality of contacts and a fastening device assembled with the housing for securing the CPU. The fastening device generally comprises a pressing member for pressing the CPU and a retaining member for securing the pressing member. Generally, the retaining member is a frame seated around the housing and including an opening for receiving the housing therein, such electrical connector is found in U.S. Pat. No. 6,877,990 issued to Liao on Apr. 12, 2005. The retaining member of Liao '990 is integrally formed with metal material. Moreover, the retaining member may be of an assembled set, which has two or three separated parts. The retaining member is preliminarily assembled onto the housing then mounted onto the PCB, or the retaining member is directly positioned onto the PCB. Conventional electrical connector as described above is found in U.S. Pat. No. 7,234,955 issued to Ho on Jun. 26, 2007 and U.S. Pat. No. 7,241,161 issued to Ma on Jul. 10, 2007.
U.S. Pat. No. 6,948,947 issued to Lee on Sep. 27, 2005 disclosed an electrical connector relating to the present invention. The electrical connector includes an insulative housing, a stiffener surrounding the housing, a load plate pivotably assembled with one end of the stiffener and a load lever pivotably attached to the other end of the stiffener. The load plate defines a pair of pressing portions. Each of the pressing portions defines a wider part and a narrower part. During the rotation process of the load plate, the wider part firstly presses a pressing point of the IC package. Obviously, because width of the narrower part is small, strength of said narrower part is lower. Thereby, strength of the whole load plate is reduced and problem of stress concentration easily occurs in region of the narrower part. Accordingly, mechanical and electrical connection between the electronic package and the printed circuit board is unsteady.
In view of the above, an improved electrical connector that overcomes the above-mentioned disadvantages is desired.